diff --git a/src/mame/drivers/stactics.c b/src/mame/drivers/stactics.c
index ce7c37d813b..e349d1147f7 100644
--- a/src/mame/drivers/stactics.c
+++ b/src/mame/drivers/stactics.c
@@ -173,7 +173,7 @@ static INTERRUPT_GEN( stactics_interrupt )
 
 static ADDRESS_MAP_START( main_map, ADDRESS_SPACE_PROGRAM, 8 )
     AM_RANGE(0x0000, 0x2fff) AM_ROM
-    AM_RANGE(0x4000, 0x47ff) AM_RAM
+    AM_RANGE(0x4000, 0x40ff) AM_MIRROR(0x0700) AM_RAM
     AM_RANGE(0x5000, 0x5000) AM_MIRROR(0x0fff) AM_READ_PORT("IN0")
     AM_RANGE(0x6000, 0x6000) AM_MIRROR(0x0fff) AM_READ_PORT("IN1")
     AM_RANGE(0x6000, 0x6001) AM_MIRROR(0x0f08) AM_WRITE(stactics_coin_lockout_w)